This library exposes a fast C implementation for flattening and unflattening hierarchical Python data structures. A unit test suite is included.
#!/usr/bin/env python
from flattery import flatten, unflatten
data = {
"x.y.0", "zero",
"x.y.1": "one",
"x.z" : 42
}
print unflatten(data)
>>>
{
'x' : {
'y' : [ 'zero', 'one' ],
'z': 42
}
}
<<<
assert( data == flatten(unflatten(data)) )
#!/usr/bin/env python
import sys
from flattery import unflatten
cols = [ "time", "request.method", "request.uri", "response.status", "response.size" ]
for line in sys.stdin:
fields = line.rstrip('\r\n').split(len(cols)-1)
values = dict([(cols[i],fields[i]) for i in xrange(len(cols))])
record = unflatten(values)
# do something with the record...
print record
>>>
{ 'time': '12/12/2012 12:00:00',
'request': { 'method': 'GET', 'uri': '/stuff/' },
'response': { 'status': '200', 'size': '40391' } }
...
Or suppose you have a web form for collecting several distinct blobs of data at once, like a payment form:
#!/usr/bin/html
<form method="post" action="">
<div>
First name: <input type="text" name="contact.firstname" value="" />
Last name: <input type="text" name="contact.lastname" value="" />
Email: <input type="text" name="contact.email" value="" />
</div>
<div>
Credit Card Type: <select name="payment.cctype"> <option> ... </option> </select>
Number: <input type="text" name="payment.ccnumber" value="" />
CCV: <input type="text" name="payment.ccv" value="" />
Expiration Month: <select name="payment.ccmonth"> <option> ... </option> </select>
Expiration Year: <select name="payment.ccyear"> <option> ... </option> </select>
</div>
<div>
<input type="submit" name="submit" />
</div>
</form>
In the form processing code, you can expand the key value form data pairs into a nested object:
#!/usr/bin/env python
from flattery import unflatten
params = formdata() # however you get a dictionary of form data...
data = unflatten(params)
print data
>>>
{ 'contact':
{ 'lastname':'Doe',
'firstname': 'John',
'email':'[email protected]' },
'payment':
{ 'cctype': 'amex',
'ccnumber': '4111111111111111',
'ccv': '4321',
'ccmonth': '12' ,
'ccyear' : '2020' } }
(But be careful with multiply-valued form data.)
Another web example, where a user is editing tabular data:
#!/usr/bin/html
<form method="post" action="">
<div>
<ul class="table">
<ul class="row">
<li><input type="checkbox" name="rows.0.delete" /></li>
<li><input type="text" name="rows.0.name" value="" /></li>
<li><input type="text" name="rows.0.email" value="" /></li>
</ul>
<ul class="row">
<li><input type="checkbox" name="rows.1.delete" /></li>
<li><input type="text" name="rows.1.name" value="" /></li>
<li><input type="text" name="rows.1.email" value="" /></li>
</ul>
...
<ul class="row">
<li><input type="checkbox" name="rows.99.delete" /></li>
<li><input type="text" name="rows.99.name" value="" /></li>
<li><input type="text" name="rows.99.email" value="" /></li>
</ul>
</ul>
</div>
<div>
<input type="submit" name="submit" />
</div>
</form>
(You should validate that the embedded indices are below some reasonable limit to avoid a memory DoS.)
In the form processing code:
#!/usr/bin/env python
from flattery import unflatten
params = formdata() # however you get a dictionary of form data...
data = unflatten(params)
print data
>>>
{ 'rows':
[
'delete': '1',
'name': 'John Doe',
'email': '[email protected]',
],
[
'delete': '0',
'name': 'Suzy Q',
'email': '[email protected]',
],
...
[
'delete': '0',
'name': 'Charlie Chaplin',
'email': '[email protected]',
],
}
Ubuntu / Debian users:
#!/bin/sh
fakeroot ./debian/rules binary
dpkg -i ../python-flattery*.deb
If there's no "real" packaging for your system yet:
#!/bin/sh
./setup.py build_ext --inplace
./test.py
./setup.py build
./setup.py install